7 parts
The backend cutover for v0.5 — the borrowed-String double-free that took six revisions to kill, why each revision grew the C++ walker registry, and how I convinced myself it was safe to delete a 1,568-file MLIR subtree and lower straight from MIR to LLVM IR.
A walk down the actor stack in v0.5. Why I deleted the `<-` send operator, how a method call lowers to spawn/send/ask through an execution context, and how supervision fires `#[on(crash)]` with the real trap code.
Native and wasm32 share the same MIR and the same textual LLVM IR — they only diverge at the TargetMachine. That makes most of WASM support genuinely free. This is about the parts that weren't — traps, blocking recv, timers, and a use-after-free that only exists on WASM.
The machine construct in detail — what the front end checks before a single instruction is emitted, how a state declaration becomes a tagged-union LLVM layout, and why I'd rather reject an illegal transition at compile time than catch it at runtime. Includes the parts that don't fully work yet.
The distributed substrate for v0.5 — replacing a hand-rolled binary wire format with a CBOR envelope described by a CDDL schema, deleting 2,498 lines of wire.rs, and giving the cluster a phi-accrual failure detector that adapts instead of a fixed timeout. Plus cross-node sends that stay type-checked.
How Hew's memory model actually works underneath — single ownership with compiler-inserted drops, strings as copy-on-write refcounted values over a header-aware allocator, and arithmetic that traps with distinct exit codes instead of wrapping silently.
How Hew lowers generics, told as the evolution it actually was — from stamping out one mangled LLVM function per instantiation, through unifying dispatch under a single call authority, to representing an abstract type parameter directly in MIR so a generic body can lower once even when its type is never made concrete.